US 12,413,204 B2
Acoustic wave device, filter, and multiplexer
Takashi Matsuda, Tokyo (JP)
Assigned to TAIYO YUDEN CO., LTD., Tokyo (JP)
Filed by TAIYO YUDEN CO., LTD., Tokyo (JP)
Filed on Feb. 17, 2023, as Appl. No. 18/170,944.
Claims priority of application No. 2022-027876 (JP), filed on Feb. 25, 2022.
Prior Publication US 2023/0275566 A1, Aug. 31, 2023
Int. Cl. H03H 9/17 (2006.01); H03H 9/02 (2006.01); H03H 9/13 (2006.01); H03H 9/56 (2006.01); H03H 9/70 (2006.01)
CPC H03H 9/173 (2013.01) [H03H 9/133 (2013.01); H03H 9/568 (2013.01); H03H 9/706 (2013.01); H03H 9/02031 (2013.01)] 10 Claims
OG exemplary drawing
 
1. An acoustic wave device, comprising:
a first piezoelectric layer that is a rotated Y-cut lithium tantalate substrate and has a first thickness;
a second piezoelectric layer that is a rotated Y-cut lithium niobate substrate, is stacked on the first piezoelectric layer, has a second thickness that is less than the first thickness, and has a spontaneous polarization direction that is substantially opposite to a spontaneous polarization direction of the first piezoelectric layer;
a first electrode provided on an opposite surface of the first piezoelectric layer from the second piezoelectric layer; and
a second electrode that is provided on an opposite surface of the second piezoelectric layer from the first piezoelectric layer, at least a part of the first piezoelectric layer and at least a part of the second piezoelectric layer being interposed between the first electrode and the second electrode.